This invention relates to a rotatable jet propulsion for a watercraft and more particularly to an improved arrangement for permitting servicing of a jet propulsion unit contained in a tunnel beneath the hull of a watercraft.
The use of jet propulsion units for powering watercraft is well known as are the advantages of such units. One of the advantages of jet propelled watercraft is that they are able to operate in extremely shallow bodies of water. However, because of their shallow water operation, jet propulsion units frequently may ingest foreign material into the impeller that requires removal for servicing. In addition, it is desirable to be able to position the jet propulsion unit, when not be employed to propel the watercraft, in an out of the water position to prevent encrustation and formation of barnacles or the like on the water inlet passages of the jet propulsion unit.
A wide variety of arrangements have recently been proposed for permitting movement of the jet propulsion unit from its normal propulsion system to a raised out of the water position. When the jet propulsion unit is positioned in a tunnel beneath the hull of a watercraft, it is particularly important to insure that the jet propulsion unit is fully elevated when it is not being utilized to propel the watercraft. Prior art systems have employed arrangements which not only rotate the jet propulsion unit, but which also tilt it so as to achieve this result. However, such compound movements are, obviously, somewhat complicated.
It is, therefore, a principal object of this invention to provide an improved and simplified jet propulsion unit for a watercraft that may be conveniently moved from a propulsion position to an out of the water position.
It is a further object of this invention to provide a jet propulsion unit that is movable between its operative and storage positions by pure rotation about a longitudinal axis.
It is a further object of this invention to provide an improved arrangement for mounting a jet propulsion unit for rotation about a single axis so that it can be conveniently moved between its propulsion position and an out of the water position.
As has been previously noted, when jet propulsion units are employed for watercraft, it is convenient to position them in a tunnel beneath the hull of the watercraft. Also, the advantages of providing movable support for the jet propulsion unit so that it may be moved out of the water either for servicing or for storage purposes also been noted. The types of devices previously employed for effecting such movement have generally been positioned within the tunnel of the watercraft and hence are subjected to the water in which the watercraft is operating. This can give rise to obvious problems.
It is, therefore, a further object of this invention to provide a drive arrangement for operating a movably supported jet propulsion unit wherein the drive mechanism is positioned within the hull of the watercraft and not in contact with the body of water.
It is a further object of this invention to provide a remotely operated power arrangement for moving a jet propulsion unit between a propulsion position and an out of the water position and wherein the power device is not disposed in the body of water in which the watercraft is positioned.